A national study of parents found that parents with multiple parenting roles -- such as those in blended families -- are at higher risk of depression. Specifically, parents with three roles were 57 percent more likely to be depressed than those with just a single parenting role.

Scholars at Brigham Young University and Princeton conducted research that gives a better look at how various types of parents experience stress. One finding of the study is that some stepfathers -- those with multiple family roles -- experience the highest stress levels.

"If you say parenting and depression, the first thing people think of is post-partum moms," said Kevin Shafer, a professor of social work at BYU. "But both moms and dads experience stress and certain kinds of parenting roles can be very, very stressful."

Shafer and Princeton's Garrett Pace analyzed data from more than 6,000 parents around the country. The main finding of the study is that depression risk increases for both men and women when the number of parenting roles they hold increases.

Parents in a "yours, mine and ours" family hold three parenting roles: one each for the two families that blended, and a third when a child is born into the blended family. The study found parents with three roles were 57 percent more likely to be depressed than those with just a single parenting role.

Shafer said that there's inherently bumpiness that comes with the process of blending two different families.

"There are norms that govern parenting, but there aren't norms for being a stepparent," Shafer said. "Am I supposed to be an actual parent, a friend, or something like a cool uncle?"

The risk is even higher for fathers in such blended families when a father has biological children who don't live with him. Shafer says that's driven partially by feelings of guilt for spending more time with his new children than his older children. The dynamic also shifts when a new baby comes along.

"The stress doesn't come from a bad place," Shafer said. "It actually comes from a really good place. They want to be a good parent, they want to be a good stepparent, and they want to be a good new parent."

Two trends underscore the importance of these findings. The first is that men are less likely to seek professional counseling when they need it. The second is that blended families are becoming more common, so more parents feel the burden of holding multiple roles.

As a social worker, Shafer hopes these findings will help more parents seek help they need. Mental health professionals should also recognize that depression can manifest in a variety of ways.

"We hope clinicians recognize that parents aren't just a homogeneous group," Shafer said. "Parents show symptoms of depression in different ways than non-parents do."

The new study is published in the journal Social Work. This study follows a 2013 paper by Shafer that the The New York Times highlighted in a post called "What Makes a Successful Stepfather."

Pace collaborated with Shafer while a student in BYU's Master of Social Work program. He graduated in in 2013 and now works at Princeton's Center for Research on Child Wellbeing.